How and which product do I apply to metal and plastic pots and faders?.....

Apply DeoxIT® 100% spray (D100S) or DeoxIT® 100% liquid (D100L-25C) according to package directions, and manipulate the channels several times (40-50) to distribute the solution and assist in breaking up the surface oxides, sulfides and other contaminants.

The following day, if the surface is still not as responsive as it should be, repeat the above step.